Sash cord repairs and replacement
A broken sash cord is the most common fault we are called out for.
The cord carries a cast iron weight inside the box frame, and when it snaps the sash drops, sticks, or will not stay up. It is usually a small job: the sashes and beads come out, the box is opened, new cord is fitted and the window is rebalanced. The frame stays in the wall and the work is done from inside the room.
London · Sash cord repairsWritten quotationsA studio of The Barnsbury Group, established 1980
How you know a cord has gone
The sash will not stay where you put it, or it falls shut on its own. It feels suddenly heavy to lift. You may have heard a thud inside the frame when it went. On a two-cord sash, one broken cord makes the window sit crooked and bind in the frame. If both have gone, the sash will not move at all.
What we do
- 01Remove the staff beads and take out the lower sash, then the parting beads and upper sash if needed.
- 02Open the pocket in the box frame and recover the weights.
- 03Check the weights are the right size for the sash. If they have been lost, which happens where a window has been worked on badly in the past, we supply new ones to match.
- 04Fit new waxed cotton cord to both sides of the sash, not just the broken one. A cord that has lasted eighty years will not last another five, and opening the box twice costs more than doing it once.
- 05Check the pulleys run freely and replace them where they are worn.
- 06Rebalance so the sash opens and closes easily and stays where you put it.
- 07Refit the beads, ease the sash, and test the window with you.
Why we replace both cords
Opening the box frame is most of the work. The second cord is the same age as the first, under the same load, and will fail within a few years. Replacing one and leaving the other means paying for the same access twice.
Cords, chains and what we use
We use waxed cotton sash cord, which is what these windows were built with and what runs quietly over a cast iron pulley. Chain is used on very heavy sashes, where the weight would wear cord out quickly, and we fit it where the window calls for it.
Cost and time
We quote per sash after a survey, because opening the box often shows other work: rotten bottom rails, worn pulleys, missing weights, or a sash that has been painted shut. A single sash is usually a visit; a whole house is quicker per window because the team is already there.
What it does not fix
New cords will not stop a draught or a rattle, which are gaps rather than balance, and they will not fix rot. If the survey finds soft timber at the bottom rail or cill, we say so and quote the repair, because new cords in a rotten sash is money spent twice. Where the window needs more than cords, see sash window restoration.
Common questions
How much does it cost to replace a sash cord in London?01
It is quoted per sash after a survey, because opening the box frame often reveals other work. It is one of the smaller jobs we do.
Can you replace a sash cord without taking the window out?02
Yes. The sashes and beads come out, but the box frame and the window stay in the wall, and the work is done from inside the room.
My sash falls shut on its own. Is that a cord?03
Usually. A sash that will not stay up has either lost a cord or lost its balance, because a weight is missing or the wrong size. Both are fixed at the same visit.
Do I have to replace all the cords in the house?04
No. We quote per sash and you choose. That said, cords in one house are usually the same age, so if one has gone the others are not far behind.
Can you repair just one window?05
Yes. A single sash is a normal call-out.
Book a survey
Send us photographs of your windows and we'll tell you what needs doing and what doesn't, with a written quotation. The digital survey is free.